1. Field of the Invention
The present invention relates generally to devices for sealing connections between two pipes or conduits while allowing for thermal expansion of one or both of the pipes, and more specifically relates to devices for sealing connections between waste gas pipes of sinter machines or similar apparatus with a gas collecting main.
2. Prior Art
Pipelines, particularly hot gas pipelines, such as waste gas pipes of sintering machine or other metallurgical aggregate apparatus, change their length during operation due to thermal expansion. In addition, they often are subject to vibration. In order to compensate for these thermal expansions and to avoid the occurrence of unacceptably high tensions or permanent deformations, extension compensation members have to be inserted. These extension compensation members have to allow for movements of the pipelines in radial as well as in axial directions. Furthermore, an explosion protection device is required in some cases.
Extension compensation members made of soft materials are susceptible to mechanical and chemical attacks, and with dust carrying gases there is a danger of hardening of such materials. Extension compensation members of flexible metallic material require high construction length, and higher restoring forces occur. With dust carrying gases, there is also the danger of clogging.
One extension compensation member is shown in German Auslegeschrift 1,180,705. This device consists of two pipe sockets attached concentrically to the pipe ends which interlock with radial intervals, one of which carries a disc-shaped clamping surface fixed to its end against which a seal ring, attached to the other pipe socket, is pressed with adjustable spring pressure. The clamping device is supported on the other pipe socket whereby the clamping surface is provided at the connection end of the inner pipe socket. The seal ring and its clamping device are provided at the free end of the pipe socket and the seal ring is arranged so that it can be adjusted. With this device, one slight axial displacement can be compensated since the axially acceptable play which equals the height of protection of the seal over its cylindrical guide surface is limited by the material related low dimensional stability of the seal material. This device is also not suitable as an explosion protection device.